The present invention relates to a backplane connector assembly for electrically connecting circuit boards together and a method for producing the plug connector component of the connector assembly.
A connector for connecting two circuit boards together has been frequently used for the purpose of enhancing an actually mounted density of the electronic circuits or for the purpose of arranging a plurality of circuit boards in a solid state in conformity with the miniaturization or reduction in size of electronic equipment.
In general, this type connector is composed of a plug connector and a receptacle connector. The plug connector is to be connected to one of the circuit boards and the receptacle connector is to be connected to the other circuit board. The types of connection between the two circuit boards using such a connector may be generally categorized into two. One type is that both connectors are clamped by a pair of circuit boards under the condition that the circuit boards are overlapped and connected to each other. The other type is where the surface of one circuit board is intersected substantially perpendicular with the surface of another circuit board when both connectors are connected to each other.
For instance, the latter substrate connecting connector is disclosed in Japanese Patent Application Laid-Open No. Hei 8-288019 and Japanese Patent Application Laid-Open No. Hei 10-172652.
In case of this type of backplane connector, there are the following tasks to be solved in view of the fact that a multi-pin connector having a large number, from several tens to several hundreds, of terminals is used recently, the connector becomes a high speed transfer connector and so on.
The first problem is that of providing effective electromagnetic shielding of signal terminals. Even in a conventional backplane connector, there are some cases where a partial approach is effected in regard to electromagnetic shielding. However, such an approach is not satisfactory. For instance, there is a receptacle connector in which a plurality of rows of signal terminals (signal pins) are provided in a widthwise direction of the connector housing, and a plurality of stages thereof are provided in a thickness, or vertical, direction of the housing. In this connector, shielding plates are arranged simply in the widthwise direction of the housing and separated from each other at designated intervals. For this reason, there is a problem of cross-talk between the signal terminals in the areas where no shielding plates are provided.
The second problem is in the manufacturing equipment and manufacturing cost of the plug connector. For instance, in a plug connector provided with a number of contacts arranged in a grid of 25 pins (widthwise) and 5 pins (height or vertically) of the plug housing, a method is carried out in which this large number of contacts, or terminals, are sequentially press fitted into the mounting holes of the connector housing in groups. In this case, the terminals and the shielding plates are alternatively press fitted, but because the shielding plates are inserted in the vertical direction, only one vertical columns of five terminals can be press fit vertically at once. As a result, the press fit steps for the terminals and the press fit steps for the shielding plates have each to be performed twenty-five times, for the terminal columns and vertical shielding plates, respectively, i.e., fifty times in total. Correspondingly, the manufacturing equipment becomes worn over time and also the manufacturing cost increases. Of course, also in this case, the above-described problem of electromagnetic shielding is still unresolved.
The present invention is directed to a backplane connector construction that overcomes the aforementioned disadvantages.
It is therefore a general object of the present invention to provide an improved backplane connector for solving the problem of the shielding of the connector and the problem of cross-talk or the like.
Another object of the present invention is to provide a technology to remarkably reduce the press inserting step of the terminals, thereby enhancing the connector manufacturing equipment and to make it possible to reduce the manufacturing cost.
These and other objects and advanatages are accomplished by way of the structure of the invention.
In accordance with the principles of the present invention, a backplane connector for electrically connecting together two circuit boards, or backplanes, together is provided with a plug connector for mounting on one circuit board and a receptacle connector for mounting on the other circuit board. The receptacle connector is provided with a housing having an opening into which the plug connector may be inserted, and it includes a plurality of male terminals arranged in a grid within the receptacle housing. The plug connector is provided with a plurality of female terminals, each terminal having a contact portion for electrically contacting the respective male terminals of the receptacle connector, and an insulative housing for holding the terminals in place. A plurality of vertical shielding plates to be arranged in parallel with each other are provided between the respective pin terminals in the receptacle connector. A plurality of horizontal shielding plates are arranged in spaced apart horizontal rows and are provided to intersect with the vertical shielding plates in a cruciform manner, within the body of the plug connector. Slits for receiving the vertical shielding plates are respectively formed in the housing of the plug connector and in the horizontal shielding plates.
According to the present invention, since the plurality of horizontal shielding plates are arranged generally in parallel with each other in the plug connector so as to intersect with the vertical shielding plates on the receptacle side in a cruciform manner, it is possible to make a form in which the shielding plates are present and adjacent to every signal terminal. Thus, it is possible to solve problem of the electromagnetic shielding of the connector and there is no problem of cross-talk or the like.
According to the present invention, when each of the pin terminals of the receptacle connector and the contact portions of the plug connector terminals are electrically connected to each other, the periphery of the respective contacts areas of the two connector terminals are surrounded by both vertical and the horizontal shielding plates of the two connectors and thus prevention of cross-talk is more ensured.
The housing of the plug connector according to the present invention is preferably composed of a plurality of insulative housing modules that are overlapped in a plurality of stages in a thickness direction (vertically) of the housing and are connected to each other, and the horizontal shielding plates are respectively interposed between the housing modules. With such a structure in which the plurality of the housing modules are overlapped in the plurality of stages in the thickness direction of the housing, it is possible to reduce the number of the housing modules. Furthermore, the horizontal shielding plates are disposed between adjacent housing modules so that the plurality of horizontal shielding plates may readily be provided.
It is also preferable that mounting holes, or passages, for the terminals are arranged at intervals widthwise of the housing modules and the slits are provided between adjacent terminal-mounting passages in the respective housing modules. The slits are provided between the adjacent mounting passages of the housing modules so that each shielding plate of the receptacle connector may be inserted into the plug connector body portion between adjacent mounting passages thereof.
It is preferable that engagement portions are provided on the housing modules so they will engage adjacent housing modules. With these engagement portions, it is possible to readily and detachably engage the housing modules together without permanently adhering the housing modules together.
It is also preferable that each housing module is provided with a plurality of terminal assemblies with contact portions that are press-fit into each mounting hole and tail portions that extend out of the module for connecting the terminals to the circuit board. With such an arrangement, it is possible to insert the terminal assemblies into the housing modules as a horizontal group so that a large number of terminal assemblies corresponding to one lateral, or horizontal, row of the plug connector may be press-fit simultaneously, rather than being limited to individual insertions of vertical columns of terminal assemblies.
It is preferable that the a portion of the terminal assembly is molded of resin or plastic except for the contact and tail portions. With such a resin molded portion, it is possible to keep each terminal in an electrically insulated condition while maintaining the terminals in one piece under the one lateral row condition.
It is preferable that a length dimension of each of the housing modules is substantially the same, a length dimension of the terminal assemblies located in an upper module is longer than a length dimension of the terminal assemblies located in a lower module, and the tail portions are bent at a right angle relative to the contact portions so that the tail portions are directed downwardly. With such an arrangement, it is easy to perform the soldering work when the plug connector is actually mounted on the circuit board. This is a suitable embodiment as the plug connector of the backplane connector where the circuit boards are at right angles to each other. It is also preferable that the molded portion of the terminal assemblies is formed to be bent substantially at a right angle as viewed in side elevation Thus, it is possible to realize the positioning work of the tail portions directed downwardly with the resin molded portion that may readily be manufactured.
On the other hand, a method for producing a plug connector according to the present invention uses a plurality of housing modules connectable with each other in a plurality of horizontal stages, with a horizontal shielding plate provided between each pair of adjacent housing modules, and terminal assemblies connected to the rear end of each of the housing modules, and comprises the following first through fifth steps: a first step of press fitting a first contact terminal assembly from a rear end side of the lowermost first housing module under the condition that the horizontal shield plate is slid onto on the first housing module; a second step of bending downwardly a rear portion of said horizontal shielding plate; a third step of overlapping a second housing module on the horizontal shielding plate of the first housing module and connecting it to the first housing module; a fourth step of press-fitting the second terminal assembly from a rear end side of the second housing module under the condition that another horizontal shielding plate is slid onto the second housing module; and, a fifth step of bending downwardly a rear portion of the second horizontal shielding plate.
According to the manufacturing method of the present invention, the plurality of housing modules are connectable with each other in the plurality of laminated stages, the horizontal shielding plates are provided between the adjacent housing modules, and the terminal assemblies are inserted through a rear end side of each of the housing modules. In the assembling work, because the upper stage housing module is overlapped and coupled through the horizontal shield plate to the lower housing module, it is possible to press insert all the terminals in one lateral row simultaneously. Accordingly, the press-fitting steps of the terminals corresponds to the number of the laminate stages of the plug connector housing. For instance, if the number of the laminate stages is five, the step of press-fitting the terminals will be repeated only five times. Thus, it is possible to considerably reduce the steps of press-fitting the terminals to thereby enhance the manufacturability and reduce the manufacture cost of the connector.
It is preferable that a step where each horizontal shield plate is provided on each housing module is performed in advance. Thus, it is possible to reduce the number of the steps of assembling corresponding to this.
It is preferable that mounting passages for the terminal assemblies are arranged at an interval in a widthwise direction of the housing modules and the slits are provided between the adjacent mounting holes. The slits are thus provided between the adjacent mounting holes so that each vertical shield plate of the receptacle connector may be inserted between the adjacent mounting holes.
It is preferable that a male-type engagement portion and a female-type engagement portion be provided for engaging with each other and for coupling the housing modules together along adjoining surfaces of the adjacent housing modules. Thus, it is possible to make the assembling work extremely convenient by assembling the housing modules in laminate in order.
It is preferable that each terminal assembly is provided with a contact portion to be press inserted into each mounting hole and a tail portion that is a lead-out conductive member for connecting each tail portion to the circuit board and the terminal assembly is molded of resin except for said contact and tail portions. With such a resin molded portion, it is possible to keep each contact in an electrically insulated condition while maintaining the terminals in one piece under the one lateral row condition. Furthermore, it is possible to keep the terminal assemblies in the electrically insulated condition from each other.
These and other objects, features and advantages of the present invention will be clearly understood through a consideration of the following detailed description.